Note: when the system has no data or have enough copies of the disk, can take offline the device

[root@freenas] ~# zpool offline datastore ada3[root@freenas] ~# zpool status pool: datastore state: DEGRADEDstatus: One or more devices has been taken offline by the administrator. Sufficient replicas exist for the pool to continue functioning in a degraded state.action: Online the device using 'zpool online' or replace the device with 'zpool replace'. scan: none requestedconfig: